$1.$ What is the break$-$even point in unit sales and dollar sales? $3.$ Angie has decided that she must earn a profit of $$28,000$ the first year to justify her time and effort. How many pairs of sandals must be sold to attain this target profit? $4.$ Angie now has two salespersons working in the store$$one full time and one part time. It will cost her an additional $$9,000$ per year to convert the part$-$time position to a full$-$time position. Angie believes that the change would increase annual sales by $$39,200.$ Should she convert the position? Use the incremental approach. $5.$ Refer to the original data. During the first year, the store sold only $3,000$ pairs of sandals and reported the following operating results:

Sales $(3,000$ pairs$)$ $ $84,000$

Variable expenses $42,000$

Contribution margin $42,000$

Fixed expenses $28,000$

Net operating income $ $14,000$

a$.$ What is the store$$s degree of operating leverage?

b$.$ Angie is confident that with a more intense sales effort and with a more creative advertising program she can increase unit sales by $50\%$ next year. Using the degree of operating leverage, what would be the expected percentage increase in net operating income if Angie is able to increase unit sales by $50\%?$